The present invention relates to an acceleration sensor and in particular to an acceleration sensor having a switching mechanism using a semiconductor microworking technology.
In recent years, acceleration sensors have been used as means for indirectly detecting an action force of impact, etc., without coming in direct contact with an object. The acceleration sensors cover various applications; it is desired that the acceleration sensor is compact and lightweight, does not require a mounting space on an object, and operates precisely and reliably.
As a predetermined acceleration detection sensor, a sensor using a conductive sphere displaced according to acceleration and connecting two contacts by the conductive sphere is disclosed in Japanese Utility Model Laid-Open Nos. Hei. 4-136575 and 4-127574.
However, the mechanical acceleration switch connecting two contacts by a conductive sphere becomes large in the outside shape because of its structure, so it is poor in responsiveness and it has an accuracy problem. If such a mechanical acceleration switch is miniaturized, batch processing cannot be performed in the manufacturing process and the mechanical acceleration switch becomes expensive.
Further, such a mechanical acceleration switch uses a movement of a sphere caused by acceleration, thus chattering occurs at the operation time.